Chaotic travelling rolls in Rayleigh–Bénard convection

Pramana

Mahendra K Verma¹  Daniele Carati²  Arnab K De⁴  Supriyo Paul1¹  Vinayak Eswaran⁴  Krishna Kumar³ 

[1] Department of Physics, Indian Institute of Technology, Kanpur 208 016, India$$;Physique Statistique et Plasmas, Universit ́e Libre de Bruxelles, B-1050 Bruxelles, Belgium$$;Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302, India$$;Department of Mechanical Engineering, Indian Institute of Technology, Kanpur 208 016, India$$

关键词: Convection;    travelling rolls instability;    direct numerical simulation.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

In this paper we investigate two-dimensional (2D) Rayleigh–B ́enard convection using direct numerical simulation in Boussinesq fluids with Prandtl number 𝑃 = 6.8 confined between thermally conducting plates. We show through the simulation that in a small range of reduced Rayleigh number 𝑟 (770 < 𝑟 < 890) the 2D rolls move chaotically in a direction normal to the roll axis. The lateral shift of the rolls may lead to a global flow reversal of the convective motion. The chaotic travelling rolls are observed in simulations with free-slip as well as no-slip boundary conditions on the velocity field. We show that the travelling rolls and the flow reversal are due to an interplay between the real and imaginary parts of the critical modes.

【 授权许可】

Unknown